Biorhythm calendar



FIG. 1 is a front elevational view of a combined biorhythm calendar withinterpretive illustrations, showing my new design;

FIG. 2 is a side elevational view thereof; and

FIG. 3 is a top plan view thereof.

The opposite side of FIG. 1 is plain and unornamented.

The ornamental design for a biorhythm calendar, as shown and described. 